In the olden days of railroad transportation, the rails were directly fastened to wooden railroad ties with railroad spikes. At turnouts, crossovers, crossings and switches, where there are special support and securing requirements, special fasteners were used to allow fastening of the rails to the support structure. Such special fasteners are described in U.S. Pat. No. 1,126,530 to Liebmann.
Trackwork fasteners of the resilient-type flexibly attach the railroad rail to a supporting structure such as a railroad tie or concrete abutment. Again, at turnouts, crossovers, crossings and switches, the problem arises of how to fasten the rail at these junctures. U.S. Pat. No. 2,424,916 to Stedman describes one such method which uses a resilient base plate. Rapid transit systems which have a high voltage third rail further require the trackwork fastener to insulate the rail from the support structure. In addition, the rail is resiliently supported to provide shock attenuation and vibration isolation of the support structure. One such resilient trackwork fastener for the abovementioned rapid transit installations is described in U.S. Pat. No. 3,576,293 to Landis. In all cases, a top portion of the trackwork fastener is secured to the rail by suitable means such as the spring clips described in the commonly assigned U.S. Pat. No. 4,307,837 issued to Leingang.
Further development in the area of resilient trackwork fasteners for turnouts, crossovers, crossings and switches led to the development of the trackwork fastener described in the commonly assigned U.S. Pat. No. 5,022,584 to Sherrick, which is herein incorporated by reference. Generally, a special trackwork fastener needs to be adaptable to a large number of special trackwork situations, it needs to be simple, cost effective and easily installed with as many standard components as possible. The trackwork fastener concept also needs to be such that it can be adapted and made to fit many special trackwork situations in the field.